Firstly, sorry to hear about this.
But moving on, you need to focus and just remove all emotion from this. Don't take the "no **** given" attitude. You are now neogiating against them .
I've been through this a few times, good and bad, my other half has a number of times also and she's in senior positions.
Record everything in writing, record meetings, make notes. Let them go through their process, no matter how bad it is. That can help you down the line.
A compromise agreement should offer enhanced terms so you don't go after them for unfair dismissal etc. Also, they should always pay the legal fees for having the compromise agreeemnt checked and that should be bundled in.
To negotiate properly, you should engage a solicitor who can assist with this. You may have to front some money first, but if their process is as bad as it sounds and they've got to the stage where you are now "being made redundant" (aka they've exhausted their BS trying to put you in another role, find another place for you in company etc), then an employment solicitor letter coming in will put the willies up them.
Finally, if you are that experienced and from what I can see on here, should you be looking at a CISO level position now? That's the way to go and will be big bucks either contract or perm/interim.
If you want the name of the solicitor my other half used, I can find out. They certainly earned their worth and got a far superior package, plus in the end the company paid for the overal legal fees that had accrued.